| Message ID | 1467440540-6630-4-git-send-email-zhangchen.fnst@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2016年07月02日 14:22, Zhang Chen wrote: > We will rewrite tcp packet secondary received and sent. > When colo guest is a tcp server. > > Firstly, client start a tcp handshake. the packet's seq=client_seq, > ack=0,flag=SYN. COLO primary guest get this pkt and mirror(filter-mirror) > to secondary guest, secondary get it use filter-redirector. > Then,primary guest response pkt > (seq=primary_seq,ack=client_seq+1,flag=ACK|SYN). > secondary guest response pkt > (seq=secondary_seq,ack=client_seq+1,flag=ACK|SYN). > In here,we use filter-rewriter save the secondary_seq to it's tcp connection. > Finally handshake,client send pkt > (seq=client_seq+1,ack=primary_seq+1,flag=ACK). > Here,filter-rewriter can get primary_seq, and rewrite ack from primary_seq+1 > to secondary_seq+1, recalculate checksum. So the secondary tcp connection > kept good. > > When we send/recv packet. > client send pkt(seq=client_seq+1+data_len,ack=primary_seq+1,flag=ACK|PSH). > filter-rewriter rewrite ack and send to secondary guest. > > primary guest response pkt > (seq=primary_seq+1,ack=client_seq+1+data_len,flag=ACK) > secondary guest response pkt > (seq=secondary_seq+1,ack=client_seq+1+data_len,flag=ACK) > we rewrite secondary guest seq from secondary_seq+1 to primary_seq+1. > So tcp connection kept good. > > In code We use offset( = secondary_seq - primary_seq ) > to rewrite seq or ack. > handle_primary_tcp_pkt: tcp_pkt->th_ack += offset; > handle_secondary_tcp_pkt: tcp_pkt->th_seq -= offset; > > Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> > Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> > Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> > --- > net/colo-base.h | 2 + > net/filter-rewriter.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++- > trace-events | 5 +++ > 3 files changed, 115 insertions(+), 2 deletions(-) > > diff --git a/net/colo-base.h b/net/colo-base.h > index 62460c5..7b32648 100644 > --- a/net/colo-base.h > +++ b/net/colo-base.h > @@ -71,6 +71,8 @@ typedef struct Connection { > uint8_t ip_proto; > /* be used by filter-rewriter */ > colo_conn_state state; > + /* offset = secondary_seq - primary_seq */ > + tcp_seq offset; Fail to find the definition of 'tcp_seq'. > } Connection; > > uint32_t connection_key_hash(const void *opaque); > diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c > index c38ab24..9f63c75 100644 > --- a/net/filter-rewriter.c > +++ b/net/filter-rewriter.c > @@ -21,6 +21,7 @@ > #include "qemu/main-loop.h" > #include "qemu/iov.h" > #include "net/checksum.h" > +#include "trace.h" > > #define FILTER_COLO_REWRITER(obj) \ > OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER) > @@ -64,6 +65,91 @@ static int is_tcp_packet(Packet *pkt) > } > } > > +/* handle tcp packet from primary guest */ > +static int handle_primary_tcp_pkt(NetFilterState *nf, > + Connection *conn, > + Packet *pkt) > +{ > + struct tcphdr *tcp_pkt; > + static int syn_flag; > + > + tcp_pkt = (struct tcphdr *)pkt->transport_layer; > + if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) { > + char *sdebug, *ddebug; > + sdebug = strdup(inet_ntoa(pkt->ip->ip_src)); > + ddebug = strdup(inet_ntoa(pkt->ip->ip_dst)); > + trace_colo_filter_rewriter_pkt_info(__func__, sdebug, ddebug, > + ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack), > + tcp_pkt->th_flags); > + trace_colo_filter_rewriter_conn_offset(conn->offset); > + g_free(sdebug); > + g_free(ddebug); > + } > + > + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_SYN)) { > + /* > + * this flag update offset func run oncs typo? > + * in independent tcp connection > + */ > + syn_flag = 1; Does this really work if you have more than one tcp connections? You probably need a conn->syn_flag. > + } > + > + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK)) { > + if (syn_flag) { > + /* offset = secondary_seq - primary seq */ > + conn->offset -= (ntohl(tcp_pkt->th_ack)); > + syn_flag = 0; > + > + } > + /* handle packets to the secondary from the primary */ > + tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset + 1); Maybe I miss something, but why +1 here?
On 07/04/2016 11:16 AM, Jason Wang wrote: > > > On 2016年07月02日 14:22, Zhang Chen wrote: >> We will rewrite tcp packet secondary received and sent. >> When colo guest is a tcp server. >> >> Firstly, client start a tcp handshake. the packet's seq=client_seq, >> ack=0,flag=SYN. COLO primary guest get this pkt and >> mirror(filter-mirror) >> to secondary guest, secondary get it use filter-redirector. >> Then,primary guest response pkt >> (seq=primary_seq,ack=client_seq+1,flag=ACK|SYN). >> secondary guest response pkt >> (seq=secondary_seq,ack=client_seq+1,flag=ACK|SYN). >> In here,we use filter-rewriter save the secondary_seq to it's tcp >> connection. >> Finally handshake,client send pkt >> (seq=client_seq+1,ack=primary_seq+1,flag=ACK). >> Here,filter-rewriter can get primary_seq, and rewrite ack from >> primary_seq+1 >> to secondary_seq+1, recalculate checksum. So the secondary tcp >> connection >> kept good. >> >> When we send/recv packet. >> client send >> pkt(seq=client_seq+1+data_len,ack=primary_seq+1,flag=ACK|PSH). >> filter-rewriter rewrite ack and send to secondary guest. >> >> primary guest response pkt >> (seq=primary_seq+1,ack=client_seq+1+data_len,flag=ACK) >> secondary guest response pkt >> (seq=secondary_seq+1,ack=client_seq+1+data_len,flag=ACK) >> we rewrite secondary guest seq from secondary_seq+1 to primary_seq+1. >> So tcp connection kept good. >> >> In code We use offset( = secondary_seq - primary_seq ) >> to rewrite seq or ack. >> handle_primary_tcp_pkt: tcp_pkt->th_ack += offset; >> handle_secondary_tcp_pkt: tcp_pkt->th_seq -= offset; >> >> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> >> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >> --- >> net/colo-base.h | 2 + >> net/filter-rewriter.c | 110 >> +++++++++++++++++++++++++++++++++++++++++++++++++- >> trace-events | 5 +++ >> 3 files changed, 115 insertions(+), 2 deletions(-) >> >> diff --git a/net/colo-base.h b/net/colo-base.h >> index 62460c5..7b32648 100644 >> --- a/net/colo-base.h >> +++ b/net/colo-base.h >> @@ -71,6 +71,8 @@ typedef struct Connection { >> uint8_t ip_proto; >> /* be used by filter-rewriter */ >> colo_conn_state state; >> + /* offset = secondary_seq - primary_seq */ >> + tcp_seq offset; > > Fail to find the definition of 'tcp_seq'. > In slirp/tcp.h typedef uint32_t tcp_seq; we add this .h in colo-base.h >> } Connection; >> uint32_t connection_key_hash(const void *opaque); >> diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c >> index c38ab24..9f63c75 100644 >> --- a/net/filter-rewriter.c >> +++ b/net/filter-rewriter.c >> @@ -21,6 +21,7 @@ >> #include "qemu/main-loop.h" >> #include "qemu/iov.h" >> #include "net/checksum.h" >> +#include "trace.h" >> #define FILTER_COLO_REWRITER(obj) \ >> OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER) >> @@ -64,6 +65,91 @@ static int is_tcp_packet(Packet *pkt) >> } >> } >> +/* handle tcp packet from primary guest */ >> +static int handle_primary_tcp_pkt(NetFilterState *nf, >> + Connection *conn, >> + Packet *pkt) >> +{ >> + struct tcphdr *tcp_pkt; >> + static int syn_flag; >> + >> + tcp_pkt = (struct tcphdr *)pkt->transport_layer; >> + if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) { >> + char *sdebug, *ddebug; >> + sdebug = strdup(inet_ntoa(pkt->ip->ip_src)); >> + ddebug = strdup(inet_ntoa(pkt->ip->ip_dst)); >> + trace_colo_filter_rewriter_pkt_info(__func__, sdebug, ddebug, >> + ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack), >> + tcp_pkt->th_flags); >> + trace_colo_filter_rewriter_conn_offset(conn->offset); >> + g_free(sdebug); >> + g_free(ddebug); >> + } >> + >> + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_SYN)) { >> + /* >> + * this flag update offset func run oncs > > typo? S/oncs/once > >> + * in independent tcp connection >> + */ >> + syn_flag = 1; > > Does this really work if you have more than one tcp connections? You > probably need a conn->syn_flag. Good catch... I will fix it in next. > >> + } >> + >> + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK)) { >> + if (syn_flag) { >> + /* offset = secondary_seq - primary seq */ >> + conn->offset -= (ntohl(tcp_pkt->th_ack)); >> + syn_flag = 0; >> + >> + } >> + /* handle packets to the secondary from the primary */ >> + tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + >> conn->offset + 1); > > Maybe I miss something, but why +1 here? > > No,I miss something. + /* offset = secondary_seq - primary seq */ + conn->offset -= (ntohl(tcp_pkt->th_ack)); should be + conn->offset -= (ntohl(tcp_pkt->th_ack) - 1); (ntohl(tcp_pkt->th_ack) - 1) is the primary seq + tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset); I will fix it. Thanks Zhang Chen > > . >
diff --git a/net/colo-base.h b/net/colo-base.h index 62460c5..7b32648 100644 --- a/net/colo-base.h +++ b/net/colo-base.h @@ -71,6 +71,8 @@ typedef struct Connection { uint8_t ip_proto; /* be used by filter-rewriter */ colo_conn_state state; + /* offset = secondary_seq - primary_seq */ + tcp_seq offset; } Connection; uint32_t connection_key_hash(const void *opaque); diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c index c38ab24..9f63c75 100644 --- a/net/filter-rewriter.c +++ b/net/filter-rewriter.c @@ -21,6 +21,7 @@ #include "qemu/main-loop.h" #include "qemu/iov.h" #include "net/checksum.h" +#include "trace.h" #define FILTER_COLO_REWRITER(obj) \ OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER) @@ -64,6 +65,91 @@ static int is_tcp_packet(Packet *pkt) } } +/* handle tcp packet from primary guest */ +static int handle_primary_tcp_pkt(NetFilterState *nf, + Connection *conn, + Packet *pkt) +{ + struct tcphdr *tcp_pkt; + static int syn_flag; + + tcp_pkt = (struct tcphdr *)pkt->transport_layer; + if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) { + char *sdebug, *ddebug; + sdebug = strdup(inet_ntoa(pkt->ip->ip_src)); + ddebug = strdup(inet_ntoa(pkt->ip->ip_dst)); + trace_colo_filter_rewriter_pkt_info(__func__, sdebug, ddebug, + ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack), + tcp_pkt->th_flags); + trace_colo_filter_rewriter_conn_offset(conn->offset); + g_free(sdebug); + g_free(ddebug); + } + + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_SYN)) { + /* + * this flag update offset func run oncs + * in independent tcp connection + */ + syn_flag = 1; + } + + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK)) { + if (syn_flag) { + /* offset = secondary_seq - primary seq */ + conn->offset -= (ntohl(tcp_pkt->th_ack)); + syn_flag = 0; + + } + /* handle packets to the secondary from the primary */ + tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset + 1); + + net_checksum_calculate((uint8_t *)pkt->data, pkt->size); + } + + return 0; +} + +/* handle tcp packet from secondary guest */ +static int handle_secondary_tcp_pkt(NetFilterState *nf, + Connection *conn, + Packet *pkt) +{ + struct tcphdr *tcp_pkt; + + tcp_pkt = (struct tcphdr *)pkt->transport_layer; + + if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) { + char *sdebug, *ddebug; + sdebug = strdup(inet_ntoa(pkt->ip->ip_src)); + ddebug = strdup(inet_ntoa(pkt->ip->ip_dst)); + trace_colo_filter_rewriter_pkt_info(__func__, sdebug, ddebug, + ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack), + tcp_pkt->th_flags); + trace_colo_filter_rewriter_conn_offset(conn->offset); + g_free(sdebug); + g_free(ddebug); + } + + if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == (TH_ACK | TH_SYN))) { + /* + * save offset = secondary_seq and then + * in handle_primary_tcp_pkt make offset + * = secondary_seq - primary_seq + */ + conn->offset = ntohl(tcp_pkt->th_seq); + } + + if ((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK) { + /* handle packets to the primary from the secondary*/ + tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset - 1); + + net_checksum_calculate((uint8_t *)pkt->data, pkt->size); + } + + return 0; +} + static ssize_t colo_rewriter_receive_iov(NetFilterState *nf, NetClientState *sender, unsigned flags, @@ -105,10 +191,30 @@ static ssize_t colo_rewriter_receive_iov(NetFilterState *nf, if (sender == nf->netdev) { /* NET_FILTER_DIRECTION_TX */ - /* handle_primary_tcp_pkt */ + if (!handle_primary_tcp_pkt(nf, conn, pkt)) { + qemu_net_queue_send(s->incoming_queue, sender, 0, + (const uint8_t *)pkt->data, pkt->size, NULL); + packet_destroy(pkt, NULL); + pkt = NULL; + /* + * We block the packet here,after rewrite pkt + * and will send it + */ + return 1; + } } else { /* NET_FILTER_DIRECTION_RX */ - /* handle_secondary_tcp_pkt */ + if (!handle_secondary_tcp_pkt(nf, conn, pkt)) { + qemu_net_queue_send(s->incoming_queue, sender, 0, + (const uint8_t *)pkt->data, pkt->size, NULL); + packet_destroy(pkt, NULL); + pkt = NULL; + /* + * We block the packet here,after rewrite pkt + * and will send it + */ + return 1; + } } } diff --git a/trace-events b/trace-events index 6686cdf..5ac56f6 100644 --- a/trace-events +++ b/trace-events @@ -1927,3 +1927,8 @@ colo_compare_icmp_miscompare_mtu(const char *sta, int size) ": %s %d" colo_compare_ip_info(int psize, const char *sta, const char *stb, int ssize, const char *stc, const char *std) "ppkt size = %d, ip_src = %s, ip_dst = %s, spkt size = %d, ip_src = %s, ip_dst = %s" colo_old_packet_check_found(int64_t old_time) "%" PRId64 colo_compare_miscompare(void) "" + +# net/filter-rewriter.c +colo_filter_rewriter_debug(void) "" +colo_filter_rewriter_pkt_info(const char *func, const char *src, const char *dst, uint32_t seq, uint32_t ack, uint32_t flag) "%s: src/dst: %s/%s p: seq/ack=%u/%u flags=%x\n" +colo_filter_rewriter_conn_offset(uint32_t offset) ": offset=%u\n"